Method of producing detachable top lift



June 22, 1937. J,v R.T H. EY 2,084,791

METHOD OF PRODUCING DETACHABLE TOP LIFTS Filed June 7, 1934 Wilneau' m MMW Patented June 22, 1937 UNITED STATES PATENT OFFICE METHOD OF PRODUCING DETACHABLE TOP LIFT Mass., a corporation of Massachusetts Application June 7, 1934, Serial No. 729,463

1 Claim.

The present invention relates to detachable top lifts, and more particularly to constructions of this character employing rubber or similar yielding compounds.

The invention is concerned with a top lift for womens shoes or the like, to which is secured an attaching post or its equivalent adapted for insertion and reception in a complementary socket mounted in a heel base.

The purpose of the invention is to economically produce a top lift of rubber which may be secured to the attaching post in accurate registration therewith, with sumcient rigidity to prevent accidental disengagement during wear or use.

With this and similar objects in view, I have discovered that by combining a top lift of rubber compound with a backing of fibre or similar inextensible and relatively unyielding material in the form of a sheet, the sheet fibre backing en- 20 gages with the attaching post and forms a relatively non-yielding base or support to which the post may be attached with sufficient rigidity to afford an adequate mounting for the lift. In actual practice I find it convenient to take a 25 sheet of rubber compound of proper thickness, with a thinner sheet of fibre secured and bonded thereto by vulcanizing, cutting the individual top lifts from the continuous sheet, and thereafter assembling in a mold the top lift and post, the

assembly causing the integral prongs or claws upon the post to project through the fibre sheet and into the rubber top lift and to be clinched therein, the fibre sheet affording sulficient stability to permit substantial anchoring of the post 35 to the top lift without vulcanizing or molding thereabout.

In the accompanying drawing illustrating the preferred form of the invention, Fig. 1 illustrates a sheet of rubber compound with attached 40 fibre backing from which the individual top lift blanks are removed; Fig. 2 illustrates in sectional outline a simple mold within which the top lift blank and post are assembled and secured; Fig. 3 illustrates a perspective of the top lift with at- 45 tached post; Fig. 4 is a section in elevation through the top lift, showing the manner of clinching the prongs; and Fig. 5 is a sideelevation of the finished top lift with attached post.

Referring more particularly to the illustrated 50 embodiment of the invention, a sheet of rubber compound is indicated at ID, with a backing of fibre l2. From this sheet of compound are conveniently removed the top lift blanks [4. It will be understood that if so desired the top lifts could be individually molded with the fibre backing incorporated therein.

Each blank l4, together with a pronged post I6, is inserted within the cavity of an assembly mold l8, and subjected to pressure by a member 26 to drive the top lift upon the prongs and clinch the prongs within the body of the top lift, the fibre backing serving to promote a relatively rigid and substantial assembly.

As indicated more particularly in Figs. 3 to 5, where the finished assembly is illustrated, the composite top lift I4 is attached to the post IS in accurate registration therewith, and the integral prongs 22 pierce the fibre backing, and are clinched within the body of the rubber somewhat below the tread surface, this embedding of the prongs below the surface being due to the yielding of the rubber body in the assembly operation and the subsequent expansion of the rubber beyond the ends of the prongs after the pressure existing in the assembly operation is removed.

This form of top lift construction embodying the use of rubber compound is simple and inexpensive in its manufacture, and serves to adequately secure the top lift to the post in an accurate and predetermined relationship to the post. By virtue of this construction top lifts may be employed for replacement without the necessity for substantially trimming or otherwise modifying the dimensions or contour of the top lift to fit the supporting heel base. Although in certain cases it may be found desirable after assembly to take a light trim or finish cut on the top lift, nevertheless the top lift after its formation and attachment of the post is for all practical purposes in its finished form.

What is claimed is:

The method of producing a detachable top lift of rubber compound or the like which comprises the formation of a top lift blank from rubber compound with a permanently attached nonyielding fibre backing conforming accurately to the shape and dimensions of the blank, assembling the blank in an assembly cavity with a post having offset attaching prongs, the post and blank being held in predetermined aligned relationship, and positively forcing the blank on to the prongs until the fibre backing engages with and seats upon the shoulders formed by the offset prongs, the latter penetrating the fibre backing and rubber portion and being clinched within the rubber portion.

JAMES VERNER CRITCI-ILEY. 

